IPX1 and IPX2 Drip Tests: Water Rate, Tilt and the Ten-Minute Clock

IPX1 and IPX2 are the gentlest water ingress tests in IEC 60529, but they still produce a steady stream of disputed results. The equipment is simple, so people relax. Then the drip box turns out to be out of level, two of the orifices are blocked, and the sample has collected a puddle on one corner instead of an even rainfall.

What the two ratings actually ask for

Both use a drip box with a grid of orifices above the sample, delivering a controlled rainfall. IPX1 is 1 mm per minute with the sample in its normal position. IPX2 is 3 mm per minute with the sample tilted 15° in four directions, tested in turn.

The tilt is 15 degrees, not "roughly sloped". A wedge or an adjustable fixture with a protractor is worth having; a sample propped on a folded cloth is not. For IPX2 the four positions are usually 15° in each of two perpendicular planes, so all four sides of the enclosure get a turn facing upward.

Getting the water rate right

The rate is expressed as a depth of water over the area of the drip box, so it is verified by collecting the output over a known time and area. In practice, measure the total volume discharged per minute and divide by the box area, then confirm that the distribution is even by placing a tray of shallow cups under the orifices for a minute. A box with 5% of its holes blocked can still hit the right total flow while soaking one corner of the sample.

• Level the drip box with a spirit level before every series; a few millimetres of tilt changes the distribution.
• Use clean, filtered water; limescale is the main reason orifices block.
• Let the flow stabilise before starting the timer; the first minute after switch-on is not representative.
• Check the water temperature; very cold water changes condensation behaviour inside a warm enclosure.

Sample condition and what to look for afterwards

Test the enclosure as supplied: glands fitted, covers torqued, drain holes in their service state, and no extra sealant added for the occasion. For IPX2, secure the sample so the tilt does not let it slide, and make sure the fixing does not press on a gasket or cover a drain.

After the ten minutes, wipe the outside and open the enclosure. Photograph the interior before touching anything. The acceptance question is whether any water that entered interferes with operation or safety — a few droplets on an internal metal wall below the entry may be harmless, while moisture on a terminal block or a PCB is not. Where the product contains insulation that could track, note the location specifically.

Condensation causes more false failures here than in the jet tests, because the water volume is small and the test is long enough for a temperature difference to matter. If the interior looks misted rather than wetted, let the sample reach ambient in a dry environment and re-inspect before deciding. A deposit of condensation is not ingress.

Keeping a record that holds up

Write down the collected flow, the levelling check, the tilt angle and positions, the exact duration, water temperature and the internal findings with photographs. When the difference between a pass and a fail is a few drops, that record is the only thing that makes the result defensible.